Various prosthetic devices have been developed for the treatment of vascular disease. These include self expanding stents that can be compressed and introduced into the vascular system using catheters. When the catheter is positioned percutaneously or by other techniques at the required site, the stent is released and the catheter is withdrawn.
The stents or prostheses have been developed to treat particular forms of vascular disease including weakened or occluded blood vessels or arteries. The treatment of a stenosis or aneurysm, for example, using a tubular prosthesis can reduce the risk of an embolism or rupture of the aneurysm. In an abdominal aortic aneurysm, for example, a bifurcated tubular sleeve can be used to maintain blood flow between the aortic artery and the iliac arteries.
However, a continuing need exists for further improvements in devices and methods of using implantable prostheses for the treatment of various conditions.
This invention relates to an implantable prosthesis including a membrane or filter and a fluid flow channel to control the flow of fluid through a body lumen. A preferred embodiment of the invention uses a mesh membrane connected to a stent and, more particularly, to a stent used to bypass an aneurysm. In a preferred embodiment of the invention, the fluid flow channel, or stent, is coupled to the filter. The device includes, in a preferred embodiment, a frame having a plurality of struts, the struts conforming to the shape of the inner wall of a vessel, a membrane covering the struts, at least one tubular prosthesis or stent being aligned with and connected to an aperture in the membrane and an attaching mechanism that connects the membrane to the tubular section.
In one embodiment, the device is collapsible to fit inside a catheter. In a preferred embodiment, the device is collapsible to a diameter of 12 French or less. The frame and/or the tubular prosthesis can be a device such as that described in International Application No. PCT/DE/00226 filed on Jan. 24, 1998, and also described in U.S. application Ser. No. 09/250,714, filed on Feb. 16, 1999 the entire contents of these applications being incorporated herein by reference. The stent and the frame of the filter or membrane can comprise a shape memory material such as a nickel-titanium alloy.
In a preferred embodiment, the frame comprises a double coil as described and illustrated in the above incorporated applications. One of the coils can be covered with a membrane material. In one embodiment, there can be an oblique angle between the two coils up to and including, for example, a 90-degree angle.
The struts of the frame can radiate outwardly from a center point of the frame. In this embodiment, the perimeter formed by the struts conforms to the shape of the inner wall of a vessel. In a preferred embodiment, the shape of the perimeter formed by the struts is circular. In another preferred embodiment, the struts comprise a plurality of loop shapes.
The membrane material can comprise either a mesh material or a non-permeable material. In a preferred embodiment, the membrane material extends beyond the perimeter formed by the struts of the frame. The additional membrane material allows the vessel to become completely sealed to prevent leakage between the membrane and the vessel wall.
The stent can comprise a flexible material. In a preferred embodiment, the device comprises two stents to be used to bypass an aneurysm located at a bifurcation. The stent can also comprise an attachment mechanism to secure an end of the stent to the membrane.
The stent can be attached to the membrane and/or a vessel wall using an adhesive such as a polymer. The polymer can also be used to secure the stent to a double coil membrane. After insertion of the prosthesis, the adhesive can be injected in fluid form into the cavity with a catheter and then hardened in situ.
The invention also relates to a method for treating a body lumen using an implantable prosthesis. The invention can relate to a method for deploying a prosthesis within a body lumen. This method can include the use of one or more catheters to deploy the elements of the prosthesis. The invention can also relate to a method for attaching at least one stent to a membrane. This method can involve deploying a membrane in a vessel, forming an opening or aperture in the membrane, and connecting a stent to the membrane wherein the tubular path through the stent is coaxially aligned with the aperture.